Binary decoding system



l1g 12, 1952 c. H. HOEPPNER 2,607,005

BINARY DECODING SYSTEM n Filed Maron 22, 195o 2 SHEETS- SHEET 1 All Mlwm mm C. H. HOEPPNER BINARY DECODING SYSTEM Aug. 12, 1952 2 SHEETS-SHEET 2 Filed March 22, 1950 /a'a M u u L E! LJ L1 mg J l. m//U/lor I@ I 8 w U e J 4Z. IL Uil m\mm has ,m59 M59 Patented Aug. 12, 1952 BINARY DECODING SYSTEM Conrad H. Hoeppner, Waltham, Mass., assigner to Raytheon Manufacturing Company, Newton, Mass., a corporation of Delaware Application March 22, 1950, Serial No. 151,132

(Cl. Z50-27) claims. 1

This invention relates to conversion of binary coded numbers to pulse position or pulse time intelligence.

In many instances, it becomes desirable to convert binary coded numbers to pulse time or pulse position intelligence. For example, When information has been converted to binary code, as to take advantage of transmission or storage in this form, it may be desirable to reconvert the information to its original form; or it may be desirable to change such information from one time base to another. Also pulse time and pulse position intelligence is readily adaptable for automatic graphical representation of the contained information.

Pursuant to the present invention, a relatively simple arrangement having a high degree of accuracy is provided for the conversion of binary coded numbers to pulse time or pulse position intelligence. For each of the digits in the code, a dual control grid tube is used. All of these dual control grid tubes are connected in parallel across a comparator circuit. The comparator circuit is so biased that only when current flow in all of the dual control grid tubes has stopped is an output pulse effected. A register circuit for each of the digits in the code is arranged to bias 'a control grid of the dual control grid tube corresponding to the same digit. The connection is so arranged that a binary number registered in the register circuits will cause a bias on the corresponding control grids so as to start current iiow in the tubes in accordance with the complement of the number in the register. In one embodiment of the invention, the other control grid of each of the dual control grid tubes is connected to conventional counting circuits which count pulses from a pulse source and continuously bias the corresponding'control grids so as to stop current flow in the dual control grid tubes in accordance with the count at any given moment. Thus, when the count in the counters equals thenumber registered in the registers, all of the dual control grid tubes will, for the rst time, have ceased conducting thereby causing the comparator circuit to emit a pulse. Other pulses may occur thereafter, but are removed by a blocking oscillator in the output circuit. An arrangement is provided for starting the count in the counting circuit at a known interval, as by a synchronizing pulse. Thus, the interval between the synchronizing pulse and the output pulse is determined by the number in the registers. A circuit is also provided for clearing the registers and resetting the apparatus in preparation for a new cycle.

In a second embodiment of the invention, in place of conventional counting circuits, a delay line tapped at suitable intervals replaces some of the counting circuits. This embodiment thereby becomes particularly adaptable t0 higher counting frequencies than would normally be used in conventional counting circuits.

These and other features, processes and 0bjectsl will become more apparent from the following description taken in connection with the accompanying drawings, wherein:

Fig. 1 is a schematic View of one embodiment of the invention;

Fig. 2 shows the potential picture at the dual control grid tubes due to the counting circuits; and

Fig. 3 is a schematic view of a signal delay arrangement which when substituted for a portion of Fig. 1 enclosed in dotted lines provides a second embodiment of the invention.

Referring to Fig. 1 in more detail, dual control grid tubes I0, I2 and I4, which may be vacuum tubes of the 6AS6 type, have their respective anodes connected to line I6 and their cathodes connected to line I8. A suitable potential is maintained across lines I6 and I8, as by a battery 20. Control grids 22, 24 and 26 of tubes I0, I2 and I4, respectively, are connected to binary number registering circuits. In this instance, the registering circuits are suitable bistable multivibrator circuits 28, 30 and 32, each of which, as will be hereinafter explained, may be made to register a digit of a binary code number and impress the complement of this code number on the corresponding control grid of the dual control grid tubes. For purposes of explanation, each of the tubes I0, I2 and I4 represents a digit in the code and is represented by a 0 if it conducting, and is represented by a 1 if it is not conducting. In this manner, binary code numbers may be represented by making certain of the dual control grid tubes conductive and nonconductive as follows:

tube

code representation number is represented by 100 in the present embodiment. If desired, it could be represented by 0 1 or even 0 1 0, as by changing the position of the tubes I8, I2 and I4. The result, however, will be the same provided the representation is known and consistently followed.

Assuming that the, p otential at the other set of control grids 34, 36 and 38 is at a proper level for permitting conduction in the tubes I8, I2 and I4, current flow may be completely controlled byY the control grids 22, 24 and 28. Control grids 22, 24 and 28 are connected to the control grids of electron tubes 48, 42 and 44 of the bistable multivibrator circuits 28, 38 and 32, respectively. When the tubes 48, 42 and 44 arenonconductive, the tubes I8, I2 and I4 will also be held nonconductive. When the tubes 48, 42 and 44 are conductive, the corresponding control grids 22, 24 and 26 will have a potential suitable for making the tubes I8, I2 and I4 conductive. Initially a negative triggering pulse 46, from a source to be hereinafter described, is made to appear in line 48 which is connected through unidirectional current devices 58, 52 and 54, such as crystals or diodes, to the grids of the tubes 48, 42 and 44, respectively. The pulse 46 triggers the bistable multivibrators 28, 38 and 32 so as to clear them of any number they might be registering and so to represent a number are nonconductive, and those tubes which would be normally nonconductive to represent the same number become conductive. The multivibrator circuits 28, 38 and 32, being of the bistable type, will maintain this complement picture at tubes I8, I2 and I4 indefinitely, or until cleared by pulse 46.

The control grids 34, 36 and 38 of the dual control grid tubes I8, I2 and I4 are connected to binary counting circuits 18, 'I2 and 'I6 which are, in the present embodiment, again bistable multivibrators connected together in conventional manner to count pulses 'I8 in line 88 from an oscillator 82 and pulse former 83. The oscillator 82 is, in this instance, controlled by another bistable multivibrator 84 so that when a synchronizing pulse 88 occurs in line 88, the bistable multivibrator 84 is made to cause the oscillator 82 to generate a fixed frequency signal which isl formed into pulses 'I8 by the pulse former 84. When a pulse 98 occurs in line 92 from a source to be' hereinafter described, it causes the bistable multivibrator to stop the generation of pulses I8 in line 88. The multivibrator circuits 18, 'I2 and 'I6 as to reset them to a Zero condition. In this instance, the zero condition is when no current flows in tubes 48, 42 and 44. Thus, also initially, no current will flow in the tubes I8, I2 and I4. The circuits 28, 38 and 32 being bistable multivibrator circuits, when any of tubes 48, 42 and 44 become nonconductive, those of the tubes 56, 58 and 68 become conductive which are in the corresponding multivibrator circuit; and inversely when any of tubes 56, 58 and 68 become nonconductive, those of tubes 48, 42 and 44 in the same multivibrator. circuits become conductive. Initially, because of triggering pulse 46, all of the tubes ,56, 58 and 68 are conductive. Any of tubes 56, 58 and 68 may be made nonconductive by yinserting a negative triggerpulse 62 in those of lines 64, 66 or 68 running to the corresponding grid of these tubes. For example, if negative pulse 62 is made to appear in line 64,' the tube y56 is thereby triggered to become nonconductive. This will-cause a rise in potential atk the anode of tube 56 which thereby raisesthe potential in the grid of tube 48 so as to cause conduction in tube 48. Conduction in tube 48 causes a drop in potential at its anode which reduces the grid potential of tube 56. The result is that tube 56 thereby remains nonconductive and tube 48. remains conductive; and as explained, the grid 22 oftube I8 is at a proper potential for causing conduction in tube I8 when tube 48 is conducting.

l Using the above table of vbinary code numbers in the present embodiment, the number three may be registered in the multivibrator circuits 28, 38 and 32 by producing a pulse 62 in the lines 64 and 66. These pulses, as explained above, will cause tubes 48 and 42 to become conductive and will produce a positive bias on control grids 22 and 24 so las to permit current flow in dual control grid tubes I8 and I2. Only tube I4 will remain nonconductive. The above explained numbering picture at dual control grid tubes I8, I2 and I4 may be represented by 0 0 1 which is seen to be not the code number for three shown in the table above, but rather the complement ,of the number three. By complement is meantthat those tubes which would normally be conductive are connected to the control grids 34, 3E and 38, respectively, in a manner similar to that explained with regard to the registering circuits 28, 38 and 32. Thus, when the tubes 94, 96 and 98 are conducting, control grids 34, 38 and 38, respectively, will have a proper potential for permitting conduction in the dual control grid tubes I8, I2 and I4, respectively. Assuming triggering pulse 98 occurs at a time when tubes 94, 96 and 88 are conducting, the oscillator 82 thereby having been stopped, no further pulses 'I8 will appear in line 88'. The circuits '18, I2 and 'I4 being bistable multivibrators, the tubes 94, 96 and 98 will remain conducting, and therefore the grids 34,

n 36 and 38 will be at a proper potential for perwill occur in line 88. The iirst counting pulse 'I8 will extinguish tube 94 and thereby cause tube |88 in the multivibrator circuit I8 to become con-v ductive. The drop in potential at the anode of the tube |88 will extinguish the tube I8. The

" second counting pulse will extinguish tube |88 through line 88 triggers the grid of tube 94 to cause it to become nonconductive and` tube |82l remains conductive. On this third count, it 'is noted that tubes 94 and 96 are nonconductive and therefore dual control grid tubes II) and I2 are both nonconductive. Thus, at that instant,

lforthe rsttime. all three of the dual control grid tubes I8, I2 and I4 become nonconductive. A potential lrise thereby occurs between lines I6 and I8 which exceeds a bias from voltage divider resistances |84 and |86 at a comparator device |88, such as a diode, which thereby `starts conducting and causes a sharp rise in potential 'at the point shown by curve ||2.'This rise in potential, due to the capacitor ||4 and resistances |06 and ||5, appears as a pulse ||6 in line ||8. Pulse ||6 is amplied by a pulse amplifier ||9 and appears as output pulse |20 from the blocking oscillator |22. Further counting pulses 18 occurring in line 80 may thereafter cause additional pulses in line ||8. Howeven they wil not appear in the output because the blocking oscillator |22 is designed with a suiiiciently long time delay to cover lsubsequent pulses which may appear beforel the circuits are again reset for another number in the register circuits for a succeeding cycle. In the present embodiment, the pulses T8 will continue to appear in line 80 and be counted in the counting circuits '10, 'l2 and 14 until the last tube 98 in the -Y counting circuit `causes a pulse 46 to appearin line 46, which appears in line 92 as pulse 90, and triggers the multivibrator 84 so as to stop further pulses 18 from being generated in lineV 30.- Also, as explained above, the pulse 46 inline 48 resets the register circuits 28, 30 and 32. The circuits are then in condition for the start of a new cycle similar to that explained above. It should be noted that the last tube 98 Will produce the pulse 46 when the potential at its anode drops. This Will occur when the tube 98 becomes conductive and represents a count of one number higher than the maximum possible count in the counting circuits. In the present embodiment of three digits, the pulse 46 would occur at the count of eight. Upon reaching this count, all of the tubes 94, 96 and 98 become conductive and represent a zero condition in the counters. Thus, when the count reaches this Zero condition, the pulses '10 cease to appear in line 80 and the counter remains at zero until a new cycle is initiated, as explained above. This cyclic picture at the dual control grid tubes may be seen in Fig. 2. The potential picture at grids 34, 30 and 38 due to the counting circuits 10, 72 and 14 are shown by curves |24, |26 and |28, respectively. Three cycles are represented, the first ending at the line |30, the second at |32, and the third at |34. The time interval |36 represents the standby zero condition and may, or may not, be of equal duration after each cycle, depending on the timing of synchronizing pulse 86. The timing interval starts at |38 in each cycle. The potential at the grids 34, 36 and 38 for a count of three in the first cycle may be seen at the line |40.

Since the pulse |20 represents the condition when the count in the counters 10, 12 and 'I4 first reaches the binary number registered in the register circuits 26, 30 and 32, and since any time delay due to the apparatus itself is constant, the interval between the pulses 86 and |20 is proportional to this binary number and provides the intelligence interval. The time base of the interval between the pulses 86 and |20 is provided by the frequency selected for the oscillator 02.

In some instances, it may, for example, be desired to provide counting frequencies above those capable of being handled by multivibrator counting circuits. For these higher frequencies a delay line |42 in F'ig. 3 may be used for the more rapidly changing digits of the code in place of the conventional counting circuits. For example, in this instance, the delay line |42 is substituted for the counting circuits and '12. This is performed by replacing the portion shown in the dotted lines |44 in Fig. l by that shown in dotted lines |48 in Fig. 3. Points |48, |50 and |52, preferably dividing delay line |42 into four equal time interval segments, are connected through points c and b to control grids 34and 36, as shown. Unidirectional current devices |54, such as crystals or diodes, are inserted in the lines |56, |58, |60 and |62 to prevent short circuiting. The delay line |42 is connected to line at thepoint c and to the counting circuit 14 at the point d. Pulse 18 passing through delay line |42 Wil create a negative pulse `at grid 34 when it reaches the point |48.v The negative pulse at grid 34 represents the count of one as shown on the code table above. When it reaches the point |50, it creates a negativepulse at grid 36 which represents the count of two.`

When it reaches the point |52, it creates negative pulses at both grids 34 and 36 which represents a count of three. The delay line |42 preferably has a time interval such that when the pulse 18 reaches the points |64 to trigger the counting circuit 14 for the count of four, another counting pulse '18 is just entering the delay line at point |66. Thus, the potential picture at grids 34, 36 and 38 may still be represented by Fig. 2. It is seen that the delay line has increased the effective counting pulse rate thereby permitting high counting rates with relatively low frequency oscillators. The remainder of the circuit inthe second embodiment will operate, as explained, with regard to the first embodiment.

While in the present embodiments a threedigit code is used for purposes of illustration, a larger or smaller number of digits may be used equally well asy by adding or removing counting and register circuits with dual control grid tubes for each such digit in a manner similar to that herein shown and described for the three digit systems. Also, the delay line may be substituted for a smaller or larger number of digits than the two digits shown in the present embodiment.

It is intended, therefore, that this invention not be limited to the particular details of construction, materials and processes described, as many equivalents Will suggest themselves to those skilled in the art. It is accordingly desired that the appended claims be given a broad interpretation commensurate with the scope of the invention within the art.

What is claimed is:

1. A binary system comprising means for producing signal pulses, means for counting said pulses, means for registering a number in binary code, means for comparing the count on said counting means with the number on said registering means, and means for producing a signal pulse when the number on said counting means equals the number on said registering means.

2. A binary system comprising means for producing signal pulses, means for counting said pulses, means for registering a number in binary code, means for comparing the count on said counting means with a complement of the number on said registering means, and means for producing a signal pulse when the number on said counting means equals the number on said registering means.

3. A binary digital system comprising normally nonconductive means for each of the digits in said binary system, means for making those of said conductive means representing the complement of a selected number conductive. means for producing signal pulses, means for making those of said conductive means representing the count of said signal pulses nonconductive, and means responsive to the extinguishing of all of said conductive means for causing an output signal pulse.

4. A binary digital system comprising normally nonconductive means `for each of the digits in said binary system, means for making those of said nonconduetive means representing the comrplement of a selected number conductive, means for producing xed frequency signal pulses, means for making those of saidv conductive means r'epresenting the count of said signal pulses nonconductive, and means responsive to the extinguishing of all of said conductive means for causing an output signal pulse.

5. A binary digital system comprising normally nonconductive means for each of the digits in said binary system, means for making those of said nonconductive means representing the comple# ment of a selected number nonconductive, means for* producing nxed frequency signal pulses, signal delay means for making those of said conductive means representing the count of said sig-l nal pulses conductive, and means responsive to the extinguishing of all of said conductive means for' causing an output signal pulse.

6. A binary system comprising means for producing signal pulses, means for counting said pulses, means' for registering a number in binary code, and means for comparing the count on said counting means with a complement of the number on said registering means.

7. A binary systemcomprising means for registering a number in binary code, means for producing signal pulses, means for counting said pulses, said counting means including signal delay means for they more rapidly changing digits in said counting means, means responsive to a syn-l chronizing pulse for starting the'y counting ofl said signal pulses,v means for comparing the count on` said counting means with the number on said registering means. and means for producing an output signal pulse when the number on said counting mea-nsv equals the number on said registering means.

8. A system as in claim '1 having additionally means for resetting said counting and said registering means after said output signal pulse.

9. A system as in claim 7 having additionally means for resetting said counting and said reg isteri'ngV means' after said output signal pulse and means for preventing more than one output signal pulse in any one cycle of said system.

10. In a binary digital system, dual control means for each of the digits in said code, means for impressing" upon one control of said dual control means the complement of a binary code number; means for impressing upon the other control of said dual control means said binary code number, and means responsive to the simultaneous existence of said complement and said code number on said control means for producing a signal.

CONRAD H. HOEPPNER.

Name Date Miller Sept. 10, 1946 Number 

